#!/bin/bash
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
# http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
#    limitations under the License.

CONFIG=/etc/sysconfig/prun
MODE=native
LOGLEVEL=2     # 0=error,1=warn,2=info,3=debug

function usage () {

    echo " "
    echo "This OpenHPC utility is used to launch parallel (MPI) applications"
    echo "within a supported resource manager."
    echo " "
    echo "Usage: $DELIM <options> executable [arguments]"
    echo " "
    echo "where available options are as follows:"
    echo " "
    echo "  -h        generate help message and exit"
    echo "  -v        enable verbose output"
    echo " "
    exit 1
}

function parse_config_file () {

    if [ -e $CONFIG ];then
        source $CONFIG 2> /dev/null
    fi
}

function _error () {
    if [ $LOGLEVEL -ge 0 ];then
        echo -n "[$DELIM] Error: "
        echo "$@"
    fi
}

function _warn () {
    if [ $LOGLEVEL -ge 1 ];then
        echo -n "[$DELIM] "
        echo "$@"
    fi
}

function _info () {
    if [ $LOGLEVEL -ge 2 ];then
        echo -n "[$DELIM] "
        echo "$@"
    fi
}

function _debug () {
    if [ $LOGLEVEL -ge 3 ];then
        echo -n "[$DELIM] "
        echo "$@"
    fi
}

function verify_launcher_avail () {
    if [ ! $(type -P "$1") ];then
        _error "Expected Job launcher $1 not found for $LMOD_FAMILY_MPI"
        exit 1
    fi
}

function set_variable () {

    local var=$1
    local set=$2
    
    _debug "Setting env variable: $var=$2"
    export $var="$2"
}

function launch_impi () {
    if [ $MODE == "native" ];then

	if [ ${RM} == "slurm" ];then
	    cmd="srun --mpi=pmi2 $@"
	elif [ ${RM} == "pbspro" ];then
            LAUNCHER="mpiexec.hydra"
            verify_launcher_avail $LAUNCHER

	    cmd="$LAUNCHER -rmk pbs $@"
	fi

	_info "Launch cmd = $cmd (family=$LMOD_FAMILY_MPI)"
        $cmd
    fi
}

function launch_mpich () {

    if [[ ${RM} == "slurm" ]];then
	if [[ ${OHPC_MPI_LAUNCHERS} =~ "pmix" ]];then
            verify_launcher_avail srun
            cmd="srun --mpi=pmix $@"
	else
	    verify_launcher_avail mpiexec.hydra
	    cmd="mpiexec.hydra -bootstrap slurm $@"
	fi
    elif [[ ${RM} == "pbspro" ]];then
	verify_launcher_avail mpiexec.hydra
	cmd="mpiexec.hydra -rmk pbs $@"
    else
        _error "Unknown resource manager -> ${RM}"
    fi

    _info "Launch cmd = $cmd (family=$LMOD_FAMILY_MPI)"
    $cmd

        return $?
}

function launch_mvapich2 () {
    if [ $MODE == "native" ];then

        LAUNCHER="mpiexec.hydra"
        verify_launcher_avail $LAUNCHER
	
	if [ ${RM} == "slurm" ];then
            cmd="$LAUNCHER -bootstrap slurm $@"
	elif [ ${RM} == "pbspro" ];then
	    cmd="$LAUNCHER -rmk pbs $@"
	else
            _error "Unknown resource manager -> ${RM}"
	fi

	_info "Launch cmd = $cmd (family=$LMOD_FAMILY_MPI)"
        $cmd

        local _status=$?

        return $_status
    fi
}

function setupenv_openmpi () {
    # disable plugin loader warnings if not not available
    set_variable OMPI_MCA_mca_base_component_show_load_errors 0
    set_variable PMIX_MCA_mca_base_component_show_load_errors 0

    # no tm module avail when using slurm
    if [[ ${RM} == "slurm" ]];then
	set_variable OMPI_MCA_ras ^tm
	set_variable OMPI_MCA_ess ^tm
	set_variable OMPI_MCA_plm ^tm
    fi

    # use romio for openmpi3
    if [[ $LMOD_FAMILY_MPI == "openmpi3" ]];then
	set_variable OMPI_MCA_io romio314
    fi
}

function launch_openmpi () {

    setupenv_openmpi

    if [[ ${RM} == "slurm" ]];then
	if [[ ${OHPC_MPI_LAUNCHERS} =~ "pmix" ]];then
            verify_launcher_avail srun
            cmd="srun --mpi=pmix $@"
	else
	    verify_launcher_avail mpirun
            cmd="mpirun $@"
	fi
    elif [[ ${RM} == "pbspro" ]];then
            verify_launcher_avail mpiexec
	    cmd="mpiexec -x LD_LIBRARY_PATH --prefix ${MPI_DIR} --hostfile ${PBS_NODEFILE} $@"
    else
        _error "Unknown resource manager -> ${RM}"
    fi
    
    _info "Launch cmd = $cmd (family=$LMOD_FAMILY_MPI)"
    $cmd

    return $?
}





DELIM=prun

# Parse command-line args

while getopts "hv" opt; do
    case $opt in
	h)
	    usage
	    ;;
	v)
	    LOGLEVEL=3
	    ;;
	\?)
	    echo "Invalid option: -$OPTARG" >&2
	    exit 1
	    ;;
    esac
done
shift $((OPTIND-1))

if [ $# -lt 1 ];then
    usage
fi


parse_config_file

EXEC=$1
shift
ARGS=$@

# Resource manager detection. If not specified from the config file, determine
# from locally installed packages. Like Highlander, we assume there can be only one.

if [ -z "$RM" ];then
    [[ -s /etc/pbs.conf ]] && RM=pbspro
    [[ -s /etc/slurm/slurm.conf ]] && RM=slurm
fi

if ! [ -x "$(command -v $EXEC)" ];then
    if [ ! -x $EXEC ];then
        _error "Unable to access executable -> $EXEC"
        exit 1
    fi
fi

if [ -z $LMOD_FAMILY_MPI ];then
    _error "LMOD_FAMILY_MPI environment variable must be set to desired MPI runtime"
    exit 1
fi

masterHost=`hostname -s`
_info "Master compute host = $masterHost"
_info "Resource manager = $RM"

if [ $LMOD_FAMILY_MPI == "impi" ];then
    launch_impi $EXEC $ARGS
elif [ $LMOD_FAMILY_MPI == "mpich" ];then
    launch_mpich $EXEC $ARGS
elif [ $LMOD_FAMILY_MPI == "mvapich2" ];then
    launch_mvapich2 $EXEC $ARGS
elif [ $LMOD_FAMILY_MPI == "openmpi" ];then
    launch_openmpi $EXEC $ARGS
elif [ $LMOD_FAMILY_MPI == "openmpi3" ];then
    launch_openmpi $EXEC $ARGS
else
    _error "Unsupported or unknown MPI family -> $LMOD_FAMILY_MPI"
fi







